2f(n+2)+6f(n+1)+4f(n)=0

Question

2f(n+2)+6f(n+1)+4f(n)=0

Answer 1

2fn+4f+6fn+6f+4fn=0
12fn+10f=0
2f(6n+5)=0
2f=0            6n+5=0
f=0               6n=-5
                    n=-5/6